1. Field of Invention
This invention pertains to the art of torque rods, such as are commonly used in the suspensions of motor vehicles, and more particularly to an elastomeric bushing assembly which functions as a maintenance-free ball joint.
2. Description of Related Art
Ball joints have been used in the suspensions of motor vehicles for many years. Some varieties require the use of lubricants to function properly. Others endeavor to provide good service without the need for lubricants and other maintenance. Some utilize elastomeric components to minimize metal to metal contact and provide maintenance-free service. For example, one such prior art ball joint is disclosed in International Polymer Science and Technology, 12, No. 5, 1985 reference MG 85/03/106; translation serial no. 9819.
Although ball joints currently in use have provided good service in some applications, in other applications they fail to meet the requirements of certain vehicles. Specifically, the loading associated with certain vehicles exceed the fatigue and strength properties of the ball joints. Ball joints are usually used where the joint must endure loading in radial, torsional, axial, and transverse tilting orientations. Further, because the ball joint is usually exposed to the elements, it is important that debris, such as gravel thrown up from the wheels of the motor vehicle, do not enter the assembly and damage it.
One disadvantage of the current prior art products are their inability to handle loading under certain conditions or load orientations.
A second disadvantage is their tendency to become damaged by road debris as was previously mentioned. A third disadvantage is the cost to manufacture and assemble the various components associated with the present designs.
The present invention contemplates a new and improved bushing assembly for use with a torque rod or ball joint which features fewer parts and, a lower cost of manufacture and assembly. Further, a unique feature contributes to discouraging debris from entering the ball joint and damaging the assembly. It overcomes the foregoing difficulties and others while providing better and more advantageous overall results.